It is recognized that applications of diode-pumped Q-switched solid-state lasers can be expanded by reducing the size and cost of such lasers. Reduced cost, of course, can provide that a new application can be made cost effective. Reduced size is beneficial for integration of the laser with other components required for an application.
All actively Q-switched solid-state lasers include a solid-state gain-element (crystal) in the form of a rod or disk, an acousto-optic (AO) or electro-optic (EO) Q-switching element, a polarizing element, a maximally reflecting mirror, and a partially transmitting (out-coupling) mirror. The maximally reflecting and partially transmitting mirrors form a laser-resonator (resonant cavity). These mirrors are usually referred to by practitioners of the art as end-mirrors. Additional mirrors may be required to “fold” the laser-resonator for minimizing the “footprint” of the laser.
As the pulse width of a Q-switched laser scales directly with laser-resonator length, various approaches have been taken to reducing the resonator-length of such lasers, such as coating one of the end mirrors on the gain-element. It is believed that further resonator-length reductions would require a significantly different approach to the design of actively Q-switched, diode-pumped solid-state lasers.